In order to utilize mobile network resources effectively, the 3rd Generation Partnership Project (3GPP) proposes MBMS which is a point-to-multipoint service that a data source is provided in a mobile network to send data to multiple users, thus the share of network resources is realized, and the utilization rate of network resources, particularly the utilization rate of precious air interface resources is increased. In an LTE network, the MBMS technology is called evolved MBMS (E-MBMS).
In an existing LTE network, a logical channel of an MBMS service is a Multicast Traffic Channel (MTCH), each MTCH corresponding to one session of the MBMS service. Multiple MTCHs can be mapped to a same transmission channel Multicast Channel (MCH), one or more MCHs can be mapped to a same Physical Multicast Channel (PMCH), and one PMCH is composed of a group of Multicast Broadcast Single Frequency Network (MBSFN) sub-frames.
In the existing LTE network, the concept of MBSFN area is introduced. In an MBSFN area, an MBMS service is sent by means of MBSFN, and different cells in a same MBSFN area adopt same resources, contents and time to send a same physical signal synchronously, so as to realize diversity reception gain of a receiving terminal. One or more PMCHs can be configured in an MBSFN area, one PMCH can bear one or more MCHs, and preferably one PMCH bears one MCH channel. In the LTE network, to notify user equipment (UE) of information that a certain MBMS service is going to change, the changes possibly being a session start, a service bearing update or a session stop and so on, Downlink Control Information (DCI) and MBMS-Radio Network Temporary Identifier (M-RNTI) may be sent on a Physical Downlink Control Channel (PDCCH). The UE further reads specific Multicast Control Channel (MCCH) information according to relative information in the DCI, this process is called an MCCH notification mechanism. In the existing 3GPP Release 9 technology, system information block 13 (SIB13) shows a resource configuration of MCCH notification information, including MCCH notification repetition coefficient (notification Repetition Coeff), notification frame offset (notification Offset) and notification subframe location (notification-subframe).
The logical channel MCCH is a multicast control channel, and the MCCH bears configuration information of each MCH/PMCH in an MBSFN area, including the MBSFN subframe configuration, modulation coding solution and so on configured by each PMCH channel. In the prior art, the MCCH corresponds to the MBSFN area one-to-one.
The MCCH also bears configuration information of a service, including a service ID, a session ID, a status, a Logical Channel ID (LCID) and so on. After obtaining information of a specific service by receiving the MCCH, the UE starts to receive data of the service on an MTCH. The configuration information of the MCCH is sent on a Broadcast Control Channel (BCCH) by means of a system message. If there are multiple MCCHs, each MCCH corresponds to a group of configuration information in a broadcast message.
When the UE enters an MBSFN cell, the UE will read information of the BCCH and the MCCH to obtain configuration information of MBMS services in the target cell, and then receive a required service on the MTCH. In the prior art, when the UE enters the MBSFN cell, the UE will read all the MCCHs in the cell and finds whether the MBMS service required to be received is started; if the MBMS service required by the UE is not started, the UE will monitor MCCH notification information. When the MCCH notification information (MCCH change notification) is detected, it is indicated that the MCCH will change in the next MCCH modification cycle, in the prior art, the MCCH notification information is only for a session start event, that is, only the session start event will trigger the system side to send the MCCH notification information.
During the research and practice of the prior art, it is found that the prior art has the following problems: in the solution of the prior art, if a cell belongs to multiple MBSFN areas, that is, multiple MBSFN areas have an overlapped area, then there are multiple MCCHs in the cell and each MCCH corresponds to one MBSFN area; UE enters the MBSFN cell, reads a BCCH, Electronic Service Guide (ESG) and an MCCH, and finds that a required MBMS service is not started; or the UE does not receive an MBMS service in the MBSFN area, after a period of time (it may be one or more MCCH modification cycles, during which the UE will not read MCCH information), the UE wants to receive an MBMS service, and it determines that the MBMS service required to be received is not started according to the ESG and stored MCCH information; in above two cases, the UE monitors MCCH notification information. If the UE does not know a correspondence relationship between the MBMS service and the MCCHs, it monitors notification information of all the MCCHs, but it is unable to determine a specific changed MBMS service according to the notification information, therefore the UE needs to read information of all the changed MCCHs, which will increase the power consumption of the UE having the capability of receiving an MBMS service in the overlapped MBSFN area. If the MBMS service required to be received is started, the UE will be unable to receive the required MCCH notification information, thus it will be unable to receive a required MBMS service.